1. Field of the Invention
The present invention relates to a radio channel initial transmission scheme for a mobile communication system in which a base station and a mobile station carry out communication through a radio channel, and more particularly, to a radio channel initial transmission scheme to be used in starting a set up of a radio channel between a base station and a mobile station.
2. Description of the Background Art
In the mobile communication system, a radio channel between a base station and a mobile station is used to repeatedly transmit a radio frame as shown in FIG. 1. This radio channel mainly comprises constantly necessary information such as a synchronization information for a radio channel and a transmission power control information, and other general information which is not constantly necessary such as a user information and a control information.
In a case of radio channel set up at a time of call origination/termination connection or handover start, the transmitting side in the communication of the base station and the mobile station has conventionally been transmitting not just the constantly necessary information but also the other general information over the entire period of time of the radio frame, despite of the fact that the user information and the control information are not yet provided during an initial period between a radio channel transmission start and a synchronization establishing.
Because of this unnecessary transmission of the other general information such as the user information and the control information over the entire period of time of the radio frame, including the initial period between a radio channel transmission start and a synchronization establishing during which the user information and the control information are still unnecessary, the conventional mobile communication system has been associated with a problem that this unnecessary transmission causes an unnecessary interference with respect to the other radio channels as well as an unnecessary consumption of a battery of a mobile station especially in the uplink radio channel.
In particular, in a case of the CDMA (Code Division Multiple Access) mobile communication system, an amount of interference significantly affects a system capacity so that an increase of interference can give rise to a serious problem regarding a considerable lowering of a system capacity.